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Linux kernel mirror (for testing)
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1/*
2 * Copyright (C) 2011 STRATO AG
3 * written by Arne Jansen <sensille@gmx.net>
4 * Distributed under the GNU GPL license version 2.
5 *
6 */
7
8#ifndef __ULIST__
9#define __ULIST__
10
11/*
12 * ulist is a generic data structure to hold a collection of unique u64
13 * values. The only operations it supports is adding to the list and
14 * enumerating it.
15 * It is possible to store an auxiliary value along with the key.
16 *
17 * The implementation is preliminary and can probably be sped up
18 * significantly. A first step would be to store the values in an rbtree
19 * as soon as ULIST_SIZE is exceeded.
20 */
21
22/*
23 * number of elements statically allocated inside struct ulist
24 */
25#define ULIST_SIZE 16
26
27/*
28 * element of the list
29 */
30struct ulist_node {
31 u64 val; /* value to store */
32 unsigned long aux; /* auxiliary value saved along with the val */
33};
34
35struct ulist {
36 /*
37 * number of elements stored in list
38 */
39 unsigned long nnodes;
40
41 /*
42 * number of nodes we already have room for
43 */
44 unsigned long nodes_alloced;
45
46 /*
47 * pointer to the array storing the elements. The first ULIST_SIZE
48 * elements are stored inline. In this case the it points to int_nodes.
49 * After exceeding ULIST_SIZE, dynamic memory is allocated.
50 */
51 struct ulist_node *nodes;
52
53 /*
54 * inline storage space for the first ULIST_SIZE entries
55 */
56 struct ulist_node int_nodes[ULIST_SIZE];
57};
58
59void ulist_init(struct ulist *ulist);
60void ulist_fini(struct ulist *ulist);
61void ulist_reinit(struct ulist *ulist);
62struct ulist *ulist_alloc(unsigned long gfp_mask);
63void ulist_free(struct ulist *ulist);
64int ulist_add(struct ulist *ulist, u64 val, unsigned long aux,
65 unsigned long gfp_mask);
66struct ulist_node *ulist_next(struct ulist *ulist, struct ulist_node *prev);
67
68#endif